Mica and pyrite are naturally occurring minerals that were present in some concrete blocks and hardcore used in Irish housing, particularly during the early 2000s. These minerals can cause significant structural damage over time, leading to cracking, bulging, and even the collapse of walls and floors.
Pyrite: The use of pyrite-rich aggregates in concrete blocks was identified as a problem in the East of Ireland around 2007. Homes constructed during this period, especially in counties like Limerick and Clare, are more susceptible to pyrite-related damage.
Mica: The “Mica Scandal” emerged in 2011, primarily affecting homes in County Donegal. Investigations revealed that concrete blocks from this region contained excessive amounts of muscovite mica, which caused the walls and floors of affected homes to crack, bulge, and, in some cases, start crumbling, compromising the structural integrity of the buildings.
▢ Why Mica & Pyrite matter to buyers
- Damage can worsen over time and is not cosmetic
- May lead to cracking, bulging and deterioration of walls and floors
- Can significantly affect property value, mortgage approval and insurability
- Commonly affects homes built before the mid-2010s in certain regions
▢ Common warning signs of Mica & Pyrite in Irish Homes
- Multiple cracks in walls, often stair-step, horizontal or vertical
- Bulging or bowing of internal or external walls
- Lifting, cracking or uneven ground floors
- Doors and windows sticking or going out of alignment
- Gaps forming at skirting boards or wall junctions
